Question on introducing fescue into a rye/blue lawn

The lawn is Lesco's Eagle plus Blue (70% rye, 30% blue). I'm thinking of aerating & overseeding with a Lesco turf type fescue this fall. Question is, will it blend in or will the fescue be noticeably patchy. The exisitng lawn is healthy and thick, I just want to get some more heat and drought tolerant turf going.
Thanks